Observation of monojet events and tentative interpretation
D Buskulic, D Casper, I De Bonis, D Decamp, P Ghez, C Goy, JP Lees, MN Minard, P Odier, B Pietrzyk, F Ariztazabal, M Chmeissani, JM Crespo, I Efthymiopoulos, E Fernandez, M Fernandez-Bosman, V Gaitan, L Garrido, M Martinez, T Mattison Show all
Physics Letters B | Published : 1994
A data sample corresponding to almost two million hadronic Z decays collected by the ALEPH detector at LEP has been searched for monojet events. Three events were found, in agreement with the expectation from the process e+e- → γ*vv, with γ*→fp. Two events are hadronic, the third one being an e+e- pair. All monojet masses are in excess of 3 GeV/c2, and two of the event have large transverse momenta: 18.5 and 20.3 GeV/c. These kinematic characteristics are quite unlikely in the process e+e-→γ*νν. The probability of their occurence increases substantially when processes involving further Z or W exchanges are taken into account, but still remains at the 5% level. © 1994.